Despite the early hour, countdown clocks are marking the time toward a 5:42 a.m. EDT liftoff of the SpaceX Falcon 9 rocket and Dragon spacecraft on the company’s 15th commercial resupply mission to the International Space Station for NASA.

Meteorologists with the U.S. Air Force’s 45th Space Wing are keeping an eye on the weather across the launch area, but the forecast predicts a 90 percent chance of favorable conditions.

Launch team members are stationed at consoles here at the Florida spaceport, at NASA’s Johnson Space Center in Houston and at the SpaceX control center located in Hawthorne, California. Today’s launch blog comes to you from the news center at NASA’s Kennedy Space Center, about three miles west of the launch site.

SpaceX’s 15th cargo resupply mission to the International Space Station is slated to begin before dawn Friday. Liftoff of the SpaceX Falcon 9 rocket and Dragon spacecraft is scheduled for at 5:42 a.m. EDT from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida. The Dragon is packed with more than 5,900 pounds of science and research, crew supplies and vehicle hardware.

The launch forecast predicts a 90 percent chance of favorable weather, according to meteorologists with the U.S. Air Force’s 45th Space Wing.

Join us right here on the launch blog for countdown updates beginning at 5:15 a.m.

The SpaceX Falcon 9 and Dragon spacecraft lift off from Space Launch Complex 40 on July 18, 2017, at the start of the CRS-9 mission. Photo credit: NASA/Tony Gray

NASA commercial cargo provider SpaceX is targeting 5:42 a.m. EDT on Friday, June 29, for the launch of its 15th resupply mission to the International Space Station. Packed with more than 5,900 pounds of research, crew supplies and hardware, the SpaceX Dragon spacecraft will launch on a Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Air Force Station.

Meteorologists with the U.S. Air Force 45th Space Wing predict a 90 percent chance of favorable weather at launch time. Cumulus and anvil clouds are the primary weather concerns.

Coverage of the SpaceX CRS-15 mission starts today with prelaunch events on NASA Television and at www.nasa.gov/live.

Commercial Resupply Services Mission:SpaceX CRS-15Launch:5:42 a.m. EDT, Friday, June 29, 2018Lift Off:Space Launch Complex 40 at Cape Canaveral Air Force Station in FloridaLaunch Vehicle:SpaceX Falcon 9, 230 feet-tallSpacecraft:Dragon, 20 feet high, 12 feet-in diameterPayload:Dragon will deliver supplies and payloads, including materials to directly support dozens of the more than 250 science and research investigations that will occur during the space station’s Expeditions 56.Return to Earth:After about one month attached to the space station, Dragon will return with results of earlier experiments, splashing down in the Pacific Ocean off the coast of Baja California.Payloads on Board:https://go.nasa.gov/2LymYKJ

The two-stage Falcon 9 launch vehicle lifts off Space Launch Complex 40 at Cape Canaveral Air Force Station carrying the Dragon resupply spacecraft to the International Space Station.Photo credit: NASA

A care package with more than 5,800 pounds of supplies from Earth is on its way to the International Space Station aboard a SpaceX Dragon spacecraft. The company’s 14th commercial cargo mission to resupply the space station began at 4:30 p.m. EDT with liftoff aboard a SpaceX Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida.

The Dragon spacecraft now is in orbit with its solar arrays deployed and providing power.

With the countdown clock in the foreground, a SpaceX Falcon 9 rocket lifts off from Cape Canaveral Air Force Station launching a Dragon spacecraft with supplies for the International Space Station.Photo Credit: NASA/Dan Casper

During a prelaunch news conference, Pete Hasbrook, NASA’s associate program scientist for International Space Station Program Science Office at the agency’s Johnson Space Center in Houston, praised the work of Commercial Resupply Services companies.

“The International Space Station is a world-class and multi- disciplinary laboratory in space,” he said. “Our commercial providers help in bringing our sciences forward and keep it going on space station and bringing benefits back to Earth.”

Expedition 55 Flight Engineers Norishige Kanai of the Japan Aerospace Exploration Agency, backed up by NASA astronaut Scott Tingle, will supervise the operation of the Canadarm2 robotic arm for Dragon’s capture. After Dragon capture, ground commands will be sent from mission control in Houston for the station’s arm to rotate and install it on the bottom of the station’s Harmony module.

The Dragon spacecraft will spend approximately one month attached to the space station. Unberthing and release of the Dragon from the space station is targeted for May 2. About five hours after Dragon leaves the station, it will conduct its deorbit burn, which lasts up to 10 minutes. It takes about 30 minutes for Dragon to reenter the Earth’s atmosphere and splash down in the Pacific Ocean off the coast of Baja California.

With solar panels deployed in the file photo, a SpaceX Dragon spacecraft arrives at the International Space Station with cargo for the SpaceX CRS-9 mission on July 20, 2016.Photo credit: NASA

Dragon’s solar arrays are unfurling and the spacecraft is on course to deliver more than 5,800 pounds of supplies, equipment and experiments to the crew aboard the orbiting laboratory. Arrival is scheduled for April 4 with grapple planned for 7 a.m. EDT.

Expedition 55 Flight Engineers Norishige Kanai of the Japan Aerospace Exploration Agency, backed up by NASA astronaut Scott Tingle, will supervise the operation of the Canadarm2 robotic arm for Dragon’s capture. After Dragon capture, ground commands will be sent from mission control in Houston for the station’s arm to rotate and install it on the bottom of the station’s Harmony module.

Live NASA Television coverage of the rendezvous and capture will begin at 5:30 a.m. EDT on April 4 at: www.nasa.gov/live

3 – 2 – 1 – Zero — Ignition and liftoff of the SpaceX Falcon 9 rocket and Dragon spacecraft, for the company’s 14th mission to deliver supplies, equipment and science materials to the International Space Station. The vehicle is quickly climbing away from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida.

Photo Credit: NASA/Dan Casper

The Falcon 9 rocket’s first-stage also has completed its work and has separated from the vehicle.

The countdown continues toward liftoff at 4:30 p.m. EDT. Starting at about seven minutes before launch, the Falcon 9’s engines will be chilled to condition them for the super-cold oxidizer — liquid oxygen.

About three minutes prior to liftoff, the umbilical tower-like strongback support structure will be lowered away from the rocket.

At 90 seconds, the SpaceX launch director will verify “go for launch.”

With about 60 seconds remaining, the flight computer will run its prelaunch checks and the rocket’s propellant tanks will be pressurized.

A Falcon 9 rocket stands ready for liftoff in this file photo from Cape Canaveral Air Force Station’s Space Launch Complex 40 to boost a SpaceX Dragon resupply spacecraft to the International Space Station on Dec. 15, 2017, for SpaceX CRS-13.Photo credit: NASA

Weather forecasters with the U.S. Air Force’s 45th weather squadron at Patrick Air Force Base are calling for an 80 percent chance for favorable conditions for launch. The primary launch weather concerns are flight through precipitation and cumulus clouds with the showers.

During SpaceX’s 14th Commercial Resupply Services Mission to the International Space Station for NASA, the Dragon spacecraft is packed with more than 5,800 pounds of supplies, equipment and several science investigations for the crew aboard the station.

Among the science experiments are:

Capturing Sprites and Elves
The Atmosphere-Space Interactions Monitor (ASIM) surveys severe thunderstorms in Earth’s atmosphere and upper-atmospheric lightning, or transient luminous events, from its perch on the exterior of the European Space Agency (ESA) Columbus module. These include sprites, flashes caused by electrical break-down in the mesosphere; the blue jet, a discharge from cloud tops upward into the stratosphere; and ELVES, concentric rings of emissions caused by an electromagnetic pulse in the ionosphere.

Metal Powder Fabrication
The NASA Sample Cartridge Assembly (MSL SCA-GEDS-German) experiment determines underlying scientific principles for a fabrication process known as liquid phase sintering, in microgravity and Earth-gravity conditions. On Earth, liquid phase sintering works like building a sandcastle with just-wet-enough sand. Heating a powder forms interparticle bonds and formation of a liquid phase accelerates this solidification, creating a rigid structure. But in microgravity, settling of powder grains does not occur and larger pores form, creating more porous and distorted samples than Earth-based sintering.

European Space Agency astronaut Thomas Pesquet inserts blood tubes into the Minus Eighty-Degree Laboratory Freezer aboard the International Space Station on Nov. 21, 2016. These blood samples are integral to the MARROW study, which seeks to understand the effects of prolonged immobility on the human body. The study’s findings will benefit people on Earth who live with reduced mobility, including seniors and bedridden patients.Photo credits: NASA

Testing Materials in Space
The Materials International Space Station Experiment Flight Facility (MISSE-FF) provides a unique platform for testing how materials, coatings and components react in the harsh environment of space, which includes exposure to ultraviolet and ionizing radiation, atomic oxygen, charged particles, thermal cycles, electromagnetic radiation and micro-meteoroids. The testing benefits a variety of industries, including automotive, aeronautics, energy, space, and transportation.

Patching up Wounds
Wound Healing tests a patch containing an antimicrobial hydrogel that promotes healing of a wound while acting as a scaffold for regenerating tissue. Reduced fluid motion in microgravity allows more precise analysis of the hydrogel behavior and controlled release of the antibiotic from the patch. This novel patch could serve as a non-surgical treatment for military combat wounds and reduce sepsis, or systemic inflammation, usually caused by contamination of an open wound.

Drug Development in Space
Comparative Real-time Metabolic Activity Tracking for Improved Therapeutic Assessment Screening Panels examines effects of microgravity on the metabolic impact of five different therapeutic compounds, evaluating the use of autobioluminescent human tissue culture for continuous tracking of metabolic activity without destroying the sample. This investigation determines the feasibility of developing improved pharmaceuticals in microgravity using a new method to test the metabolic impacts of drug compounds. This could lead to more effective, less expensive drugs.